Pump and filter apparatus for a chemical toilet



P 1967 N. J. PALMER 3,343,178

PUMP AND FILTER APPARATUS FOR A CHEMICAL TOILET Filed Feb. 1, 1966 2 Sheets-Sheet 1 5 [N vE/vroe A/oeeaer 1]. P/JLMEQ Sept. 26, 1967 N. J. PALMER PUMP AND FILTER APPARATUS FOR A CHEMICAL TOILET 2 Sheets-Sheet 2 Filed Feb. 1, 1966 United States Patent 3,343,178 PUMP AND FILTER APPARATUS FOR A CHEMICAL TOILET Norbert J. Palmer, Playa Del Rey, Califi, assignor to Monogram Industries, Inc., Culver City, Calif. Filed Feb. 1, 1966, Ser. No. 524,300 4 Claims. (Cl. 4--115) ABSTRACT OF THE DISCLOSURE A toilet system having a rotating pump element in a rotating filter basket with both being rotated by a single motor for recirculating flushing liquid, the motor being of the reversible type having its output shaft connected to a pump impeller which cooperates with a pump housing to produce a flow of such liquid from a tank through the filter element and into said housing, in that order, regardless of the direction of rotation of said motor output shaft, the filter basket being driven through a speed reduction unit and a slip friction clutch to prevent overheating of the motor in the event that the speed of the filter basket is reduced appreciably or stopped.

The present invention relates generally to a recirculating sanitation system. It relates more particularly to pump and filter appparatus for such a system. This application is a continuation-in-part of US. Application Ser. No. 438,500, filed Mar. 10, 1965, in the name of the same inventor.

Self-contained recirculating toilet systems have found a wide application in aircraft, marine vessels, trailers and campers and the like. Typically such a system includes a toilet bowl and a tank that is in communication with the bowl and only partially filled with a quantity or batch of a liquid chemical solution. After each use of the toilet, whereby liquid and/ or solid waste material is deposited in the bowl, a generally determined amount of liquid is recirculated from the tank to the bowl to flush or wash the waste material into the tank. In addition to the waste material, toilet paper and various other foreign articles, objects or material may be thrown into the toilet, and the liquid also washes this foreign material into the tank. As the toilet is used, more and more liquid waste is added to the liquid in the system. The chemical solution in the liquid acts on the waste or foreign material to break it down, to mask undesired odors, and to generally digest or neutralize the waste material. While the tank itself is periodically emptied and cleaned of such waste material, solids, paper and the like, and the liquid in the system replaced with a fresh batch of solution, the value of such as a system depends to a considerable extent on the ability of the system to operate repeatedly using the same batch of solution and without requiring cleaning of the system or changing of the solution. As a corollary to this, it is necessary that the filter arrangement be capable of effectively functioning for a like long time period during which is provided a sufiicient quantity of solution for each flush of the bowl.

One of the problems presented in such a system is effectively filtering the quantity of liquid which is circulated to the bowl so that relatively clear liquid leaves the tank, with solid waste and foreign material being retained in the tank. This is desirable from an esthetic viewpoint, but more importantly is necessary to protect the functioning of the pumping mechanism and to keep the conduits or lines clear. It will, of course, be appreciated that some particels of solid waste and foreign material will be included in the liquid which is recirculated. The terms liquid and solution, as used herein, refer generally to the mixture of liquid waste and liquid chemical solution together with such particles.

3,343,178 Patented Sept. 26, 1967 Material and particles tend toaccumulate at the inlet to the pumping means, and such accumulation tends to limit the amount of liquid which can be circulated or delivered to the bowl when the system is operated or flushed. From the point of view of filtering, one of the most severe problems is caused by toilet or tissue paper which tends to decompose or fragment into small fibers or particles which then tend to accumulate or compact at the inlet to the pumping means to limit its intake.

Certain prior devices have attempted to alleviate such problems by periodically reversing the flow of solution in the system. This approach has not proved particularly satisfactory. A more successful approach to the problem has been the use of a filter arrangement having mechanical wipers or scrapers with relative movement being provided between the wipers and the filter to physically scrape or remove material which tends to accumulate on the filter. While such an arrangement has proved commercially effective, material tends to accumulate at one side of the wipers and to impair the full efi'iciency of the device.

In addition to such problems from the gradual accumulation of particles, there is some danger that the filer arrangement will become locked or jammed so that it is slowed or even stopped, and inasmuch as it is physically connected to the output of the motor, will cause the motor to burn out. To meet this danger, clutch devices have been utilized between the motor and the filter ar rangement to permit the motor to operate freely of a jammed filter arrangement. However, the prior art devices have usually produced a loud sound or noise, such as a clicking, when the filter arrangement becomes jammed. This can be annoying, disturbing and even alarming to nearby people, particularly when the sanitation system is installed in a passenger aircraft and the noise occurs during the flight of the aircraft.

Prior sanitation systems of this type have other disadvantages and deficiencies.

Accordingly, it is an object of the present invention to provide a novel and improved sanitation system construction.

A further object of the present invention is to provide a novel and improved pump and filter apparatus for a recirculating sanitation system.

A more specific object of the present invention is the provision of such a pump and filter apparatus which is self-cleaning.

Another object of the present invention is the provision of means that protect the drive motor should the filter arrangement become jammed or locked, but do not produce an accompanying loud noise or sound to disturb or alarm nearby people.

A further object of the present invention is the provision of a compact, simple and economical pump and filter apparatus of this type which is effective, durable and dependable.

Various other objects and advantages of the present invention will become more apparent from the following description and the accompanying drawings.

Broadly, the present invention contemplates a novel and improved pump and filter apparatus for a recirculatin-g toilet system. The apparatus includes a reversible, mechanical wiper-type filter arrangement which may be reversed incident to the operation of the apparatus to effect self-cleaning of the filter arrangement. The apparatus may be constructed and arranged so that the reversal and accompanying cleaning of the filter arrangement takes place simultaneously with the pumping of liquid through the system.

Very broadly, a presently preferered form of the pump and filter apparatus of the present invention includes a pump means which will move substantially the same volume of liquid material in the same pre-determined direction for either direction of pump rotation. The apparatus also includes a self-cleaning filter arrangement comprising a filter means and wiper means. Relative lateral movement between the filter and wiper means causes the wiper means to scrape away material that tends to accumulate on the filter means; A single reversible motor is operatively connectedto the pump means and to the filter arrangement to drive both in forward or reverse direction in accordance with the directionof rotation of the motor. Thus, reversing the motor reverses the relative movement of the filter arrangement so that the arrangement is self-cleaning. The motor reversal also reverses the pump means, but, as noted above, the pump means continues to move liquid in the same direction.

A relatively silent clutch arrangement is interposed between the motor and the filter arrangement. It the latter should become jammed or locked so that it was slowed or stopped, the motor would be free to rotate and would thereby be protected. The silent operation of the clutch arrangement avoids disturbing or alarming people nearby.

In the drawings:

FIGURE 1 is a partially schematic perspective view, with a part broken away to show details of construction, of portions of a self-contained recirculating aircraft toilet system that includes a pump and filter, apparatus embodying various features of the present invention;

FIGURE 2 is an enlarged side view, with parts broken away and in section, of the filter and pump apparatus shown in FIGURE 1.

FIGURE '3 is a sectional view taken generally along 33 of FIGURE 2;

FIGURE 4 is a further enlarged sectional view taken generally along line 4-4 of FIGURE 2, showing particularly the transmission means of said apparatus; and

FIGURE 5 is a sectional view taken generally along line 5-5 of FIGURE 4, which line 5-5 is arranged to show in elevation the sequence of elements in said transmission means.

T he over-all sanitation or toilet system FIGURE 1 illustrates schematically portions of a self-.

contained recirculating toilet system for use in a large passenger aircraft. The illustrated system includes. the presently preferred form of pump and filter apparatus which is designated generally by the numeral 10. It will be appreciated that there are various other applications for such a system and apparatus, such as in boats, trailers, campers, trains, or the like.

As shown in FIGURE 1, the system includes a tank or reservoir 12 which is generally rectangular in shape having an upper wall 14, a lower wall 16 and vertical side walls 18. Initially, the tank 12 is only partially filled with a quantity or batch of liquid chemical solution. As the system is used, the level rises to a level such as indicated by lines a--a in FIGURES 1 and 2 or even higher before the liquid is removed and a fresh batch of solution added. The tank 12 may be constructed of any suitable material which will withstand the corroding, deteriorating and rusting effect of the chemical solution and thewaste material which the tank will hold. A generally standard frusto-conical toilet bowl 20 is mounted in the upper wall 14 of the tank, and suitable means (not shown) provide communication from the bowl to the tank.

As noted generally above, after each use of the toilet, the pump and filter apparatus is actuated to deliver a determined quantity of relatively clear liquid from the tank 12 to the bowl to wash the waste material from the bowl and to facilitate its passage into the tank. In the tank, the solution acts on the waste material to gen erally neutralize it and cause its structural breakdown. The solution will normally include substances to reduce and/or mask the odor from the waste material both initially and during its decomposition and the solution may be colored to visually mask the waste material. The solution also acts on foreign material such as tissue paper.

General description of illustrated pump and filter apparatus As shown best in FIGURES 1 and 2, the illustrated pump and filter apparatus 10 is a compact, self-contained unit or package mounted on the upper wall -14 of the tank 12 so as to extend downwardly into the interior of the tank and to have its lower end submerged in the liquid within the tank. In general, the apparatus 10 comprises an impeller type pump 24 and a rotary filter arrangement 26. As shown in FIGURE 2, the apparatus 10 includes a casing or housing 28 that supports a reversible motor 30 above the tank. The housing 28 defines a pump passage 32 that includes an inlet 34 at the lower end of the housing below thelevel of the liquid and an outlet 36 at the upper end of the housing to connect to the bowl. A pump rotor or impeller 38 is rotatably supported in the passage 32 and directly connected to the motor by pump drive means 40. Rotation of the impeller in either direction causes liquid to flow through the passage in the same direction from the inlet to the outlet as shown generally by the arrows in the drawings. The filter arrangement 26 includes a filter 42 which is rotatably mounted at the lower end of the housing 28 surrounding the pump inlet 34.-

The filter arrangement 26 also includes. filter wiper or scraper means in the form of a pair of opposed wiper or scraper blades 44. which are secured to the lower end-of the housing for engagement with the filter 42. The housing supports filter drive means 46 for transmitting power from the motor 30 to the filter arrangement 26. The filter drive means 46 includes a gear train or transmission 48 and a silent friction-type clutch arrangement 50.

In general, in the operation of the illustrated apparatus 10, rotation of the motor in a first direction rotates the pump impeller 38 in the same direction and also rotates the filter 42 in a first direction. Reversing the motor to rotate in a second direction reverses the pump impeller.

38, however the flow continues in the same direction as indicated by the arrows noted above. The reversal of the motor reverses the direction of rotation of the filter, however, to effect cleaning of the filter 42 and the scrapers 44.

Detail description of pump and filter apparatus The housing or casing 28 which is constructed of a suitable corrosion-resistant material includes an upper gear box section 60 and a lower pump housing section 62. A circular mounting plate 64 is secured to the upper end of the gear box section 60 with the gear box section positioned eccentrically with respect to the mounting plate. A motor housing 66 is secured, as by means of bolts 68, to the mounting plate 64 generally above the gear box section 60.

The tank upper wall 14 is providedwith an aperture 70, and the apparatus 10 is inserted through the aperture 70 to position the gear box and pump housing sections 60 and 62 within the tank while the mounting plate 64 is supported by the portion of the upper tank wall surrounding the aperture. Suitable screws 72 may be used to secure the mounting plate 64 to the tank wall. The mounting plate 64 is provided with an aperture 76 generally central of the motor housing 66 for providing communication between the motor housing and the gear box section. The mounting plate 64 is recessed around the upper portion of the aperture 76 to receive a portion of the motor 30, as shown best in FIGURE 5. The mounting plate 64 is also provided with an aperture 78 for the pump outlet, as will be explained in further detail below. The aperture 78 is prvided with an annular groove 80 adapted to receive an O-ring. A suitable sealing gasket 81 is provided between the underside of the mounting plate and the upper tank wall. Suitable openings or cutouts are provided in the gasket 81 in alignment with the apertures 76 and 78.

The motor 30 is a conventional electric motor capable of reversing direction of rotation of its output shaft 82 when the direction in which current is delivered to the motor is reversed. The motor 30 is disposed within the motor housing 66 with its output shaft 82 extending vertically downwardly through aperture 76 in the mounting plate into the interior of the gear box section 60. The axis of the motor output shaft 82 will be used as a main or reference axis bb in describing the apparatus. As noted above, a portion of the motor 30 extends downwardly into the recessed area around the aperture 76.

The gear box section 60 includes a vertical side wall 84 of irregular cylindrical shape, as shown in horizontal section in FIGURE 4. The wall 84 is secured along its upper edge to the underside of the mounting plate 64 and extends downwardly through the aperture 70 in the upper tank wall. The gear box section 60 includes a horizontal lower or bottom wall 86 which is integral with the side wall 84. An intermediate horizontal wall or internal plate 88 is supported within the gear box section a short distance above the lower wall 86 to define an upper cavity or compartment 87 and a lower cavity or compartment 89. The gear box section 60 will be discussed in further detail below in connection with the pump and the filter drive means, the transmission means, and the clutch arrangement.

The lower or pump housing section 62 is generally cylindrical externally and is secured to the lower end of the gear box section 60. The pump housing section 62 is positioned eccentrically both with regard to the gear box section 60 and to the main axis b-b. A suitable spacing plate 90 is disposed between the gear box section 60 and the pump housing section 62. The spacer 90 is generally circular and coextensive with the upper surface of the pump housing section 62, to which it is secured by screws 91 (FIGURE 4). The spacer plate 90 is provided with a circular aperture 92 that is below the aperture 78 in the mounting plate 64. A large aperture 93 is formed in the spacer plate below the gear box section 60 and generally centered about the main axis bb.

The pump housing section 62 includes an annular vertical outer wall 94 formed with an upper portion 96 that is generally circular cylindrical of approximately the same diameter as the spacer plate 90. The wall 94 has also a circular cylindrical intermediate portion 98 of a smaller diameter than the upper portion. A downwardly facing annular shoulder or lip 102 is formed at the lower edge of the upper portion 96. The wall 94 is further formed with a lower portion 100 of irregular elongated shape in horizontal section as shown in FIGURE 3. There is a main downwardly facing generally annular shoulder 104 at the lower edge of the intermediate portion 98. The lower edge of the intermediate portion 98 is also formed with a second generally annular shoulder 106. Further, at the side of the vertical wall 94, adjacent the main axis bb, the lower portion of the intermediate portion 98 is provided with a recess 108 to accommodate a portion of the filter drive means, as will be described below.

The pump housing section 62 is integrally formed with an internal or intermediate horizontal wall 110, spaced upwardly a short distance from the lower edge of the exterior wall 94, and with an internal or intermediate vertical Wall 112. The intermediate walls 110 and 112, in general, separate the interior of the pump housing section 62 into two cavities or compartments: a drive means cavity or compartment 114 and a pump cavity or compartment 116. The drive means cavity 114 is open at its upper end to the aperture 93 in the spacer plate 90 and to the underside of the gear box section 60. The intermediate horizontal wall 110 is integrally formed with a hub 118 that provides a bearing 119 extending along the main vertical axis bb. The external wall 94 is formed adjacent its intermediate portion 98 to provide a bearing 121. The bearing 121 extends vertically from shoulder 106 at recess 108 upwardly into cavity 114.

A cover plate 120 having the irregular shape of the lower outer wall portion 100 (FIGURE 3) is secured by means of screws 122 to the lower edge of the exterior wall 94. The cover plate is provided with a circular opening or aperture 124 that is positioned directly below the main vertical axis bb and provides the pump inlet 34.

The cover plate 120, the intermediate horizontal wall 110, and the lower edges of the exterior wall 94 define an elongated horizontally extending section 126 of the pump cavity 116. The exterior wall 94 and the intermediate vertical wall 112 define a generally circular, vertically extending outlet section 128 of the pump cavity 116. The vertical section 128 extends generally adjacent the drive means cavity 114, extending from the end of the horizontal section 126 furthest from the main axis bb upwardly to the aperture 92 in the spacer plate 90. As shown in FIGURE 2, the lower portion of the vertical section 128 is spaced inwardly or closer to the main axis b-b than is the upper portion of the section 128. The upper and lower portions of the section 128 are connected by a generally inclined intermediate portion. The upper portion of the vertical section 128 is counterbored to provide an annular upwardly-facing shoulder 130. An annular groove 132 is formed in the section 128 above the shoulder for receiving an O-ring. The counterbored upper end of the section 128 corresponds in size and alignment with the aperture 92 of the spacer plate 90.

A generally cylindrical, vertically extending discharge tube or conduit 134 has its lower end received in the counterbore at the upper end of the vertical section 128. The lower edge of the tube 134 is supported on the shoulder 130 and an O-ring 136 is provided in the groove 132. The discharge tube 134 extends upwardly adjacent the gear box section 60 through the aperture 78 in the mounting plate 64, and through the associated hole in the gasket 81. The discharge tube 134 is formed with an annular outwardly extending rib 138 positioned immediately below the undersurface of the gasket 81. The upper end of the tube 134 extends above the mounting plate 64 and it is adapted to receive one end of a flexible hose or conduit 140 which leads to the flushing means (not shown) of.

the toilet bowl. The discharge tube 134 is thus in communication with the pump cavity 116 and together they comprise the pump passage 32.

The pump 24 also comprises the pump rotor or impeller 38 and the pump drive means 40. As shown in FIGURES 2 and 3, the impeller 38 includes a central hub 142 and a pair of flat, oppositely extending, generally rectangular blades 144. As shown in those figures, the impeller 38 is supported at one end of the horizontal cavity section 126 for rotation about the main axis bb. The tips of the blades 144 extend in generally close proximity to the adjacent cavity inner wall. It will be readily apparent that rotation of the impeller in either direction will tend to draw solution upwardly through the inlet aperture 124 and to direct it along the horizontal cavity section 126 toward the vertical cavity section 128 and thence upwardly through that vertical cavity section.

The pump is driven directly by the motor 30. The impeller 38 is fixed on the lower end of a vertical pump drive shaft 146 and the upper end of the shaft is connected to the motor output shaft 82 by a self-aligning coupling assembly 148.

The pump drive shaft 146 is rotatably supported along main axis bb. The lower end of the shaft 146 is journalled in the bearing in the hub 118 and extends downwardly into the cavity section 126 where it supports the impeller 38. As shown best in FIGURE 5, the upper end of the shaft is supported in a bearing 150 that is mounted in the intermediate wall 88 of the gear box section 60. The shaft 146 passes through the lower wall 86 of the gear box section where a suitable seal assembly or means 152 is provided. The upper end of the shaft 146 extends above the bearing 150 and has a cylindrical sleeve or retaining collar 154 releasably secured around it by means such as a set screw 156. The collar 154 rests upon the upper edge of the bearing150 to provide vertical support for the shaft 146. The upper end of the shaft extends upwardly above the collar 154 and is secured to the coupling assembly 148.

The assembly 148 includes an upper section 158 connected to the lower end of the motor shaft 82 by a set screw 160. The assembly 148 also includes a lower section 162 which is connected to the upper end of the pump drive shaft 146 as by means of a set screw 164. The sections 158 and 162 are pivotally connected together for generally universal movement by an intermediate section 166. The assembly 148 serves to compensate for minor variations in the positioning and alignment of the motor shaft and the pump drive shaft fromthe main vertical axis b--b.

As noted above, the filter arrangement 26 includes a filter 42 which is rotatably mounted on the lower end of the housing 28 surrounding the pump inlet 34. As shown in FIGURES 2 and 3, the filter 42 is a generally cylindrical upwardly open, cup-shaped solid stack filter member or basket having slotted walls: a circular horizontal lower wall 168 and a generally cylindrical vertical side wall 170. The filter 42 is a solid integral part of a suitable material such as various plastics and is formed with an internal integral ring gear 172 spaced from its upper edge of the side wall 170. The inside of the upper edge of the wall 170 above the ring gear 172 is cut back to provide an annular'recess 174. As shown at best in FIGURE 2, the filter 42 is mounted on the housing so that the lower portion of the side wall 170 and the lower wall 168 are spaced from the respective adjacent walls of the housing to provide a space or cavity 175 for the circulation and flow of liquid. The side wall 170 is formed to define a plurality of vertically stacked horizontally-extending interrupted annular slots 177. Each slot 177 formsa circular peripheral outer groove 176 extending around the outside of the filter. The outer grooves 176 expand somewhat toward the outside of the filter. Also, periodically spaced around the internal circumference of the filter, the side wall 170 is formed so as to provide vertical posts or ribs 179, which interrupt the slots 177 but not the outer grooves 176. The slots 177 and grooves 176 start adjacent the lower edge of the filter and are provided up to adjacent the upper edge of the filter, terminating just below where the filter is formed internally to provide the ring gear 172. Some slots (not shown) are also provided in the lower bottom wall 168 of the filter. The filter 42 is normally submerged below the level a-a of the liquid in the tank when the system is operative. Operation of the pump draws liquid from the cavity 175 through the opening 124. The liquid in the tank is drawn through the slots in the walls 170 and 168 into the cavity 175. Flow of liquid from the tank is illustrated generally by arrows in FIGURE 2.

The filter 42 is held in place by a pair of the wiper or scraper blades 44 that are secured to the pump housing section 62 as by means of screws 180. Each wiper blade 44 is a generally elongated, vertically-extending structure mounted at its upper end to the outside of the intermediate wall portion 98. Each blade 44 is provided at its lower end with an inwardly extending support flange 182. Each blade 44 is generally arcuate in horizontal section, as seen best in FIGURE 3, generally conforming to the contour of the outside of the filter side wall 170. A plurality of horizontally-extending vertically-spaced teeth or ribs 184 are provided on the inside of each blade to intermesh with the filter grooves 176. Each of the ribs 184 is generally arcuate in horizontal section to mate with the filter 42. A reinforcing flange 186 extends along the upper edge, down the two opposite sides of its blade, and inwardly on the opposite sides of the support flange 182. These wiper blades, which are relatively heavy-duty to minimize their flexing or deformation and are referred to as solid-stack type blades, have proven quite effective in operation in comparison to lighter-duty more flexible structures.

The blades 44 provide the scraper or wiper means for the illustrated device. Relative movement between the. filter 42 and the blades 44 serves to scrape or wipe away material accumulating on the outside of the filter and on the blades incident to the flow of liquid through the filter. Continuous rotation in one direction would tend to accumulate material at one side of the blades. For example, with the filter 42 rotating in the direction shown by the arrow in FIGURE 3, material would tend to accumulate on the filter at one edge of the blade 44 as indicated generally by the letter A. By periodically reversing the rotation of the filter relative to the blades, such accumulation can be minimized and the self-cleaning feature eifectuated.

The filter drive means 46 which transmits power from the motor 30 to the filter arrangement 26 includes, as noted above, the gear train or transmission 48 and the clutch arrangement 50. Filter drive means 46 also includes a vertically extending filter drive shaft 190 which is rotatably mounted adjacent one side of the housing 28. The shaft 190 is positioned so that a filter drive pinion 192 secured at the lower end of the shaft is in driving mesh with the internal ring gear 172 of the filter 42. The lower end of the shaft 190 is journalled through bearing 121 in pump housing wall 94. As shown best in FIGURE 5, the shaft 190 passes upwardly through the lower wall 86 of the gear box section 60, where a suitable seal assembly 193 is provided, and through a bearing 194 in the intermediate .wall 88 of the gear box section. A thrust washer 196 is secured on the shaft 190 below the bearing 121 and a thrust washer 198 is mounted on the shaft above the bearing 194 to support the shaft in position.

i The upper end of the shaft 190 extends into the upper cavity 87 of the gear box section and has secured thereon a small gear 200.

A small driving pinion 202 is secured on the pump drive shaft 146 intermediate the walls 86 and 88. As shown best in FIGURES 4 and 5, power is delivered from the pinion 202 through the gear train or transmission 48 I and through the clutch arrangement 50 to the small gear 200.

The gear train or transmission 48 is mounted on a pair of vertical shafts 204 and 206 that are rotatably supported between the intermediate wall 88 and the lower Wall 86. The driving pinion 202 drives a large gear 208 secured to shaft 204. A small pinion 210, also on the shaft 204, drives a large gear 212 on the shaft 206. A small pinion 214, also secured on the shaft 206, imparts rotation to the clutch arrangement 50 which ordinarily transmits that rotation to the small gear 200 of the filter drive means.

The clutch arrangement 50' includes a vertical shaft 220 that is journalled in bearings 222 and 224 in the respective intermediate and lower walls 88 and 86 of the gear box housing 60. The shaft 220 includes a large cylindrical center portion 226 which is received in the bearing 222, and a lower reduced diameter portion 228 which is received in the bearing 224. The shaft 220 further includes an upper portion 230 which extends upwardly into the upper cavity 87 of the gear box and has a threaded upper end 231. An idler gear 232 is fixed on the shaft 220 within the lower cavity 89 in meshing engagement with the last pinion 214 of the gear train. The idler gear 232 is supported on the center or intermediate portion 226 of the shaft by a thrust washer 234 received in an annular groove 235 adjacent the lower end of the shaft center portion 226.

A cylindrical support plate 236 in the shape of a ring is disposed on the shaft at the upper end of the center portion 226 where it extends upwardly above the bearing 222.

A clutch assembly 240 is rotatably mounted on the upper portion 230 of the shaft 220 immediately above the support plate 236. The clutch assembly 240 includes a clutch gear 242 which is of generally the same size as the idler gear 232 so that there is no change in speed of rotation between these two gears when they rotate together on the shaft 220. The clutch assembly 240 further includes a pair of generally cylindrical discs: a lower disc 244 and an upper disc 246. The discs 244 and 246 are made from a suitable high frictional material, such as clutch or brake composition. One disc is secured on each side of the clutch gear 242. The face of each disc 244 and 246 away from the clutch gear 242 has a recessed center portion so as to form an annular or ring-shaped contact surface 250 and 252, respectively.

A pressure plate 254 is positioned on the upper portion 230 of the shaft above the disc 244. The pressure plate 254 is mounted for axial movement relative to the shaft 220 but for common rotation with the shaft. More particularly, the shaft 220 extends through a central bore 256 in the pressure plate 254. A Woodrulf-type key 258 is secured to the shaft 220 so as to extend into a vertical slot 260 opening radially outwardly from the bore 256. The pressure plate 254 comprises a lower generally-flat disc-shaped section 262 and an upper hub section 264 of reduced diameter.

A torque nut 266 is threaded on the upper end 231 of the shaft 220. The nut 266 includes a lower cylindrical hub section 268 of approximately the same diameter as the hub section 264 of the pressure plate. The torque nut 266 also includes an upper hexagonal-shaped plate section 270. A coil compression spring 272 is disposed coaxially with the shaft on the hub sections 268 and 264. The spring 272 tends to urge the pressure plate 254 downwardly against the upper disc 246 of the clutch assembly 240. In turn, the clutch assembly 240 is urged downwardly so that the lower disc 244 is urged against the support plate 236 that is supported by the upper end of the bearing 222. Thus, the ring-shaped contact surfaces 250 and 252 are urged or biased against adjacent surfaces of the support plate 236 and the pressure plate 254, respectively. This serves to resiliently hold or lock the clutch assembly 240 relative to the shaft 220. Therefore, rotation imparted to the idler gear 232 rotates the shaft 220 and, in turn, the clutch gear 242 to, in turn, rotate the input pinion 200 of the filter drive means.

Should the filter arrangement become totally or partially jammed so that the gear 200 will not rotate or will be slowed, the clutch gear 242 and the entire clutch assembly 240 will also become stationary or be slowed while the shaft 220, the pressure plate 254, the idler gear 232, the gear train 48, the pinion 202 and the pump drive shaft 146, and the motor output shaft 82 all continue to rotate. Thus, the motor is protected from burning itself out due to a jammed or locked filter. The pressure exerted by the spring 272 is such that the clutch assembly 240 will normally rotate with the shaft 220, but relative movement is permitted between the disc 244 and 246 of the clutch assembly and the adjacent surfaces should the clutch assembly be slowed or stopped. The spring force exerted by coil spring 272 may be adjusted by adjusting the torque nut 266.

FIGURE 1 diagrammatically illustrates the control means for the illustrated toilet system. A power supply 280 provides electrical current to the motor 30 through suitable electrical conductors 281 (FIGURE 2). An electro-mechanical arrangement that includes timing means 282 and alternating means 284 is provided between the motor and the power supply. The timing means and the alternating means are controlled by a manually operated actuator 286. To flush the toilet, the actuator 286 is operated, which starts the timing means 282 to provide power from the supply 280 to the motor 30 for a controlled time increment. Further, the actuator 286 operates the alternating means 284 to provide current flow to the motor 30 in opposite directions for each subsequent operation of the actuator 286. Thus, the actuator 286 is operated and the reversible motor 30 is run for the predetermined time increment in a first direction. The next time the actuator 286 is operated, the motor is run in the opposite direction for that time increment. This cycling is continuously repeated. If preferred, the motor need not reverse for each alternate operation, but might be provided with means causing reversal of the motor only after a predetermined number of operations of the motor in a single direction.

The illustrated motor 30 has a capacity of over ten hours continuous running under load. Although the operation of the motor is normally intermittent rather than continuous, should the control means malfunction so that the motor did operate continuously, it is sufliciently durable to survive an extended time period until the problem is discovered. Also, the motor 30 is so designed and constructed that it will withstand a locked rotor or impeller condition for approximately four minutes.

The illustrated motor 30 has a 0.25 horsepower rating and operates at approximately 7200 r.p.m. The pump im peller is rotated at the same speed to deliver approximately 16 gallons per minute at 0.7 p.s.i. This speed is reduced in two stages: first to about 2168 r.p.m. at shaft 204 and then to about 498 r.p.m. at shaft 206. The clutch arrangement (idler gear 232 and clutch gear 242) is rotated at about r.p.m. The filter drive means (shaft is rotated at about 498 r.p.m. and the filter 42 is rotated at about 40.4 r.p.m.

The capacity of the illustrated structure to continue to pump liquid in one direction while the operation of the motor and thus the direction of relative movement of the filter arrangement is reversed, provides a highly novel and effective self-cleaning pump and filter apparatus for such a system. Also, as noted above, the construction of the clutch arrangement protects the motor should the operation of the filter become slowed or stopped, but does not create noises such as would disturb or alarm nearby people.

Various modifications and changes may be made in the illustrated structure without departing from the spirit and scope of the present invention.

Various features of the present invention are set forth in the following claims.

What is claimed is:

1. In a self-contained toilet system that includes a toilet bowl and a tank for holding the liquid of the system, self-cleaning pump-and-filter apparatus for circulating a quantity of relatively clear liquid from the tank to the bowl for return to the tank, said apparatus comprising:

(a) reversible pump means having an inlet, said pump means being positioned, constructed and arranged to draw liquid into said inlet and to deliver the liquid in the same predetermined direction from the tank to the bowl for either direction of its operation.

(b) a reversible filter arrangement including a filter means disposed outwardly of said pump inlet and filter wiper means disposed immediately outwardly of said filter means, said filter arrangement including means supporting said filter means and said wiper means for relative movement therebetween to remove material deposited on said filter means, said direction of relative movement being changed by reversal of the direction of operation of said filter arrangement to effect self-cleaning of said filter arrangement, and

(0) operating means operatively associated with said pump means and with said filter arrangement for operating both said pump means and said filter arrangement in either one direction or the other, said operating means comprising a single reversible motor means for operating both said pump means and said filter arrangement in either one direction or the other, a clutch arrangement between said motor means and said filter arrangement, said clutch! arrangement being constructed and arranged to permitsaid motor means to continue to operate should operation of said filter arrangement be stopped or 'slowed, said.

clutch arrangement being of the silent friction-type and including a shaft assembly,- a clutch assembly rotata'bly supported on the shaft assembly, and friction means frietionally connecting said clutch assembly to said shaft assembly for common rotation under normal conditions, one of said assemblies being movable with said motor means and the other of said assemblies being movable with said filter arrangement, said friction means permitting relative rotation between said shaft assembly and said clutch assembly should the relative rotation between said filter means and said filter wiper means be stopped or slowed to stop or slow the operation of said filter arrangement.

2. A toilet system as set forth in claim 1 in which said pump means includes a rotor, said rotor being coupled to the output shaft of said reversible motor means and functioning to produce a flow of liquid from said tank, through said filter arrangement and to said rotor, in that order, regardless of the direction of rotation of said reversible motor.

3. A toilet system as set forth in claim 2 in which said motor output shaft has a gear thereon, a speed reduction unit coupled to said gear and driving said shaft assembly.

4. In a self-contained toilet system that includes a toilet bowl and a tank for holding the liquid of the system, self-cleaning pump-and-filter apparatus for circulating a quantity of relatively clear liquid from the tank to the bowl for return to the tank, said apparatus comprising:

reversible pump means having an inlet, said pump means being positoned, constructed and arranged to draw liquid into said inlet and to deliver the liquid in the same predetermined direction from the tank to the bowl for either direction of its operation,

a reversible filter arrangement including a filter means disposed outwardly of said pump inlet and filter wiper means disposed immediately outwardly of said filter means, said filter arrangement including means supporting said filter means and said wiper means for relative movement therebetween to remove material deposited on said filter means, said direction of relative movement being changed by reversal of the direction of operation of said filter arrangement to effect self-cleaning of said filter arrangement, and

operating means operatively associated with said pump means and with said filter arrangement for operating both said pump means and said filter arrangement in either one direction or the other, said operating means comprising a single reversible motor means for operating both said pump means and said filter arrangement in either one direction or the other, said pump means including a rotor connected to the output shaft of said reversible motor and cooperating with the housing of said pump means to produce liquid flow from said tank through said filter means and into said pump housing, in that order, regardless of the direction of rotation of said motor output shaft.

References Cited UNITED STATES PATENTS 2,979,731 4/ 1961 Reetz 490 3,067,433 12/1962 Dietz et al. 4-90 3,172,131 3/1965 Herkenhine 4-115 LAVERNE D. GEIGER, Primary Examiner.

H. K. ARTIS, Assistant Examiner. 

4. IN A SELF-CONTAINED TOILET SYSTEM THAT INCLUDES A TOILET BOWL AND A TANK FOR HOLDING THE LIQUID OF THE SYSTEM, SELF-CLEANING PUMP-AND-FILTER APPARATUS FOR CIRCULATING A QUANTITY OF RELATIVELY CLEAR LIQUID FROM THE TANK TO THE BOWL FOR RETURN TO THE TANK, SAID APPARATUS COMPRISING: REVERSIBLE PUMP MEANS HAVING AN INLET, SAID PUMP MEANS BEING POSITIONED, CONSTRUCTED AND ARRANGED TO DRAW LIQUID INTO SAID INLET AND TO DELIVER THE LIQUID IN THE SAME PREDETERMINED DIRECTION FROM THE TANK TO THE BOWL FOR EITHER DIRECTION OF ITS OPERATION, A REVERSIBLE FILTER ARRANGEMENT INCLUDING A FILTER MEANS DISPOSED OUTWARDLY OF SAID PUMP INLET AND FILTER WIPER MEANS DISPOSED IMMEDIATELY OUTWARDLY OF SAID FILTER MEANS, SAID FILTER ARRANGEMENT INCLUDING MEANS SUPPORTING SAID FILTER MEANS AND SAID WIPER MEANS FOR 